Why are your beliefs and goals important to define? Because they set the boundaries for what you do so you can put it on autopilot. This frees you up to use your willpower on new projects, new focuses.

I've been thinking about this in the last couple of months, but not that elaborated. It was more like "make your decisions when you're a health, feeling well, motivated and generally rational". It makes no sense at all take a big life decision when you're a feeling pain, or depressed or something like that.

This insight came after I've read the "The conquest of Happiness", by Bertrand Russell, where the author talks how we lose A LOT of mental energy rethinking over things when this makes no sense: if you don't have new information, there's no reason to change opinion. He advocated to put some time apart, when you are well and rational, take the decision and forget about it.

The first 30% of the book is wonderful, by the way. The rest is really, really weak.